Attack Potency:Large Building level+ to Large Town level (Nearly killed Wan, seriously damaged Korra in her Avatar State. Accidentally destroyed small mountains in his fight against Raava). Likely Continent level via environmental destruction at full power (He was going to cover the world in darkness and then reshape it, when he possessed Unalaq he nearly managed to do so)

Speed: At least Supersonic+ (Being the progenitors of the Avatar state, they should at least be comparable to Korra/Aang in their Avatar state)

Durability:Large Building level+ to Large Town level (Took a beating from Wan and he was fine, took a beating from Korra and he was fine, crashed against small mountains and he was fine). His regeneration and immortality make him very hard to defeat, the only known way to reliably "kill him" is to make him fuse with a human and killing said human when he/she reaches the Dark Avatar State.

Stamina: Neary endless (Fought Raava for at least ten thousand years and was imprisoned inside the Tree of Time for ten thousand years)